Gravity propagates light

Photons can travel through areas without gravity, however, to see a result it has to be propagated through gravity. So if photons were to spin inside an area without gravity in reality they could be bright white, but you would see nothing. The transmission of information is propagated through gravity particles bumping together like a Newton's cradle. If you put a Newton's cradle in an area where the energy could not get out it would still work, so long as gravity was trapped in this area, and spinning. but you would never know that the energy was there to see it working.

Pincho Paxton